As an apparatus for shearing aluminum, there is disclosed Japanese Patent Application Laid-Open No. 2005-87915 “Aluminum shearing apparatus”, as Patent Document 1. Patent Document 1 discloses a shearing apparatus especially for shearing aluminum, using half-cut pyramid-shaped cutting edges each having a special cutting tooth shape. According to the description, the aluminum shearing apparatus includes one cutter unit and the other cutter unit facing each other, which are pivotally attached to a frame and have half-cut pyramid-shaped cutting edges disposed in a zigzag manner, movable means for shearing which moves the other cutter unit, an input opening for aluminum formed at free ends of the one cutter unit and the other cutter unit and a discharge opening formed via a supporting shaft disposed at base end portions of the one cutter unit and the other cutter unit, and pyramid-shaped inclined faces of the half-cut pyramid-shaped cutting edges ensure shearing of aluminum.
However, Patent Document 1 has a problem to be improved. Specifically, the lower portions of the one cutter unit and the other cutter unit are not bent and inclined. Therefore, if materials to be sheared, which are aluminum, have such shapes that cannot be sheared with the half-cut pyramid-shaped cutting edges, such as elongate materials, they may get through from the lower portions of the one cutter unit and the other cutter unit.
To solve the above problem, there is disclosed Japanese Patent Application Laid-Open No. 6-106083 “An apparatus for crushing and breaking weirs, runners, defective products or the like for casting by hydraulic pressure” in which strip-shaped cutting edges are formed on a lower end of a swinging cutter apparatus. According to the description, the apparatus for crushing and breaking weirs, runners, defective products or the like for casting by hydraulic pressure includes a stationary cutter apparatus having a number of tapered cutting edges provided in a frame which is open at the top and bottom faces thereof, a swinging cutter apparatus facing the stationary cutter apparatus and being pivotally fitted at the lower part of the frame, which has a number of tapered cutting edges which are in engaging relationship with the tapered cutting edges, a pressing means for swinging the swinging cutter apparatus and a discharge opening for discharging crushed and broken casting pieces which is provided below the swinging cutter apparatus and the stationary cutter apparatus, and at the lower end of the swinging cutter apparatus, strip-shaped cutting edges having inclined faces are formed ensuring the catching of undesired products such as elongate materials and rod-like materials.
In addition, Japanese Utility Model Application Laid-Open No 48-54557 “Crusher” is disclosed, which relates to a crusher including a fixed cutter and a movable cutter which are bent and inclined with an appropriate downward gradient at the respective lower end portions thereof. According to the description, the crusher includes a fixed cutter apparatus and a movable cutter apparatus that operates to crush materials by rotation of the eccentric shaft at the top end thereof, both cutters being opposed to each other at a predetermined engaging angle. At the respective lower ends of the fixed and movable cutter apparatuses, claw portions which are bent and inclined with an appropriate downward gradient toward the front are formed extendedly and rows of sawtooth cutting edges are laterally formed on the opposed faces of the claw portions. In this crusher, rows of cutting edges are longitudinally formed on the whole areas of the opposed faces of the fixed cutter apparatus and the movable cutter apparatus at the upper part, and rows of cutting edges are laterally formed on the whole areas of the opposed faces of the respective claw portions of the fixed cutter apparatus and the movable cutter apparatus.